Ability:Zero
by Flickering Hope
Summary: In this world, there are those bestowed with「power」. As time passed, more and more people were born with the ability to use this「power」and after a decade, 99.9% of newborns were able to wield flames, which came to be known as「Abilities」. Of those gifted, children with an immense power became known as「Wielders」. So, what happened to the other 0.01% ? They are known as「Ability:Zero」.


In this world, there are those bestowed with「power 」.

In a world wrecked by adversity, where the land itself seemed to _burn_ in an outcry at the misfortune that had befallen the mortals which lived and died within its borders, a King prayed to「God 」. He prayed for his people to be saved from the calamity which enveloped the Earth. He prayed for the power to end the futile war which claimed so many innocent lives. Against all odds, his prayer was answered. The King gave his life, and in exchange, his people gained「power 」.

This「power 」emerged in the form of flames so brilliant, so beautiful, and so very powerful. The King's three sons held the most glorious flames of all, a molten gold which burst through the night and shone the light towards victory. Their power was only rivaled by that of the son's 6 retainers, nobles from lesser families who served as the support against those who wished the main royal house harm. Each of the son's 6 most trusted retainers wielded these mystical coloured flames, each with different strengths and when their colours intermingled, it was said to resemble the halo which appears after the rain. With this newfound「power 」, they led their armies to victory and the world was divided into three kingdoms, unified at the central lands, each under the rule of a new sire. These kingdoms were named after the three sons and the lands were born anew. The youngest son, Mare, controlled the Eastern nations. The second son, Arcobaleno claimed the lands of the West. And Vongola, the eldest, held control over the largest of at the nations in the North. Each kingdom was further divided into 7 nations, each nation ruled by either one of the sons or their retainers. The central nation, only about half the size of the other lands, served as a neutral land between the 3 kingdoms, a safe haven. It was there that the Tri Ni Sette Treaty was signed.

As time passed, more and more people were born with the ability to use this「power」and after a decade, 99.9% of newborns were able to wield flames, which came to be known as「Abilities」. Though most people contained such a small amount that they could only use the most basic properties of their flames, very rarely, a child would be born who was gifted with an immense amount of power, most of them descendants from either the King's sons or their retainers. These children, who made up less than 5% of those gifted with power, came to be known as「Ability:Wielders 」. In order to teach these gifted children how to control their Ability, an academy was built in the centre of the Central Nation in order to train these「wielders 」. It was named the Tri Ni Sette Academy after the Treaty which united all the nations.

So, what happened to the other 0.01% ? In truth, it wasn't 0.01%, but closer to 0.0001%. Even rarer than「wielders 」, only 1 in more than a million children were born without the ability to use flames at all. Officially, they were given the title: 「non-wielders 」. More commonly, they are known as「Ability:Zero 」.

Such is the history of this world.

But, what if the history books lied?

What if the eldest son hid a dark secret that would be passed down his bloodline for the centuries to come?

What if the one who answered the King's prayers were not「God 」…

…but the「Devil 」?

"Itai…" Tsunayoshi Kuchiru mumbled as she rubbed the swell starting to emerge on her head after her latest fall. By the side, a group of girls giggled as they watched the small brunette gather her books which had splayed across the hallway floor. The girl who had tripped the brunette not quite able to hide a self-satisfied smirk- not that she seemed to be trying all that hard at concealing it in the first place. Other onlookers who had seen the whole ordeal weren't any more sympathetic than the instigators either.

"Hmph, serves her right."

"What? Dame-Tsuna again? As a no-good failure, the least she could do is stop tripping and getting in the way of the rest of us."

"I know right? What's a Zero like her even doing in Tri Ni Sette Academy anyway?"

Tsuna paid them no mind, already too used to such occurrences to let something of this caliber get to her. Keeping head bowed low and long brown bangs covering the majority of her face, she simply placed the gathered books back into her satchel and continued on her way back to the girl's dormitories. She knew why they hated her, and understood even better that the reason for their apparent hatred was completely beyond her control. They hated her because she was powerless. Simple as that. Well, okay, that was not quite accurate. They may have _disliked_ her because she was born without the innate ability to produce flames. After all, discrimination towards Ability:Zeros was an open dirty-little-secret in society. No, the reason they _hated_ her wasn't because she was a Zero, but because she was a Zero who was accepted into Tri Ni Sette Academy, the legendary institution which only the best of the absolute best and most gifted wielders could enter.

Since the birth of the mysterious flames more than 4 centuries ago, countless hours of research had been invested into unraveling the enigma that was the Ability. One of the findings of this research was that a person's level of Ability was decided from birth and that the level of Ability they were born with would remain the same until they died. Therefore, it is essentially impossible to train someone to gain an Ability. Due to this, children were tested the moment they were born for their level of Ability. A unit of measure for these flames were even created called the Fiamma Volt (FV) and each child's Ability was recorded on their birth certificate under a grade depending on their level. These levels generally ranged from D-A, with D signifying the most basic of Abilities and A being the highest of the general population. However, above these grades there were S-SSS flames. To receive a grade of S class was almost as rare as the chances of being a Zero. To receive SS is almost unheard of. There has only even been one recorded SSS class, the original Vongola Prince and there hasn't been one since.

Following this founded logic of life, the Tri Ni Sette Academy was not there to train children to increase their Ability, but rather teach them how to most effectively control the Ability they have. Only wielders of high grade B or above could enter the Academy, the students there were the absolute cream of the crop. Hence, a Zero such as Tsuna being allowed to attend such a prestigious Academy was naturally viewed upon with disdain. Ironically, the entire reason behind a Zero's attendance in such an institution was part of a new program instigated that year by the principle in order to assimilate wielders to those who were less gifted and to hopefully send back a representative who could in turn educate the less gifted on the humanity of wielders. The selection had held much fanfare with the name of every citizen aged 14 that year who did not meet the Academy criteria shoved into a giant glass dome before the principle himself- also the current 9th head of the Vongola Kingdom, Vongola Timoteo- drew a slip of paper among the hundreds of thousands of identical pieces of white and read out the lucky name on national television with the heads of the other two kingdoms and various nations sitting behind in a public show of support for the new program.

They really should have asked for suitable applicants to submit their names to be drawn. Then again, no one actually considered that there could be a single person in the whole universe who wouldn't kill for the chance to go to THE Academy. Tsuna really wished they had. Then she wouldn't be stuck in this situation. When a bunch of men in crisp black and white suits rocked up at her house the next morning, she'd tried to send them away, fully intending to refuse the offer, but some things in life can't be undone. Particularly things which occur on live national television with the most powerful leaders as witnesses.

 _What this program really failed to factor in,_ Tsuna mused, _was the damaged egos of the normal Academy students with a non-wielder in their midst._

Tsuna was brought out of her inner musings when she fell once more, this time of her own accord.

"Hiiieeeeee!" Tsuna let out her rather unusual yet signature squeal as she landed harshly on her backside. In truth, Tsuna was rather clumsy, so running into strangers and falling was sadly an expected occurrence in her day to day life. What was _not_ expected was the stranger to actually lend her a hand to help her up.

"Are you okay?" a gentle baritone inquired as Tsuna stared mubly at the hand in front of her, following the red-clothed hand up to view the face of an admittedly handsome Chinese man. He was garbed in a traditional red _changshan_ and had waist-long hair almost long enough to rival Tsuna's tied back in a braid, held together at the end with a red ribbon.

"Ah, I'm fine. Thank you." Tsuna replied, deciding to stop her inner monologue and accepting the outstretched hand once the man started looking at her worriedly. "I'm sorry to have caused you trouble." Tsuna bowed with her apology to the man before walking away. Tsuna really did feel bad about troubling the man as well. After all, how often had someone actually worried about her in this Academy? Well, she'd probably never see him again though. The gold clip on his shirt had sported the roman numeral two, that meant he was a high school third year. Now that Tsuna thought about it, usually that badge was worn on the collar of the school uniform along with a ribbon whose colour represented the type of flame the student wielded. Actually, she did vaguely remember the principle mentioning something in the opening ceremony about the strongest groups from each kingdom being exempt from some things, such as wearing a school uniform. She paused. _Nah, it couldn't be_. Shaking her head to rid her of useless thoughts lest she bump into a less kind stranger she once again continued her journey to her room.

* * *

"I'm home." Tsuna mumbled at the entryway to the empty room. As could be expected of a room created for a program funded by the world's leaders, the place was ridiculously huge for just one person the occupy. Up ahead form the entryway was the livingroom, fully furnished with plush couches and plasma TV stuck on the wall. To the left was the most beautiful kitchen Tsuna had ever seen, equipped with the latest appliances and complete with an eating area, it soon became the love of Tsuna's culinary life. Even further beyond the living room were two guest bedrooms and a bathroom. Needless to say, those hadn't been touched since Tsuna first arrived at the Academy and would probably stay that way until she left. On the right was Tsuna's master bedroom with ensuite, the second love of Tsuna's life with it's gorgeous bubble bath and pristine shine. It was pretty much the room of every girl's dream.

 _Though,_ Tsuna mused, _the larger the space is, the more aware one becomes of how alone they truly are. Well, we're all alone to begin with anyway, the illusion that we are anything but is just that- an illusion._

With that mildly depressing thought in mind, Tsuna headed to her room. She was tired from listening to that sorry excuse of a maths teacher drone on for the last 2 hours (really, whoever thought of double maths period should be hanged) and was really to pretty much collapse on her bed and be dead to the world for the majority of the foreseeable future. Just before she dozed off though, Tsuna lifted the small gold locket she always wore around he neck to her lips, just as she had done every night for the past 8 years. It was her reminder. The reminder for why she existed, and what she needed to protect. She buried the grief within that locket- the pain, the suffering, the sin which she must carry to the grave and beyond- all fastened under lock and key within its smooth golden walls. She could only hope that they wouldn't overflow.

* * *

All she could hear were the sounds of footsteps.

 _Thud thud thud._

Footsteps and her panting breath, her heart beating so loud it was hard to differentiate whether those were the sounds of her pursuers gaining on her, or the beats of her own pitiful attempts to survive.

Left.

Then right.

Right again.

NO, don't go up the stairs- you'll just be cornered.

She just needed to- THERE!

Taking a sharp left, she burst through a small door at the end of the deserted hall, slamming the door behind her as her knees finally gave in and she slid to the ground, back pressed against the door as the footsteps of her pursuers faded away as they passed by. Breathing a sigh of relief, she glanced up for the first time only to find that she was not quite as alone as she had originally thought. Staring back at her were 8 pairs of eyes. Strangely enough, she felt no malice as she had expected, just unconcealed curiosity. Sighing, she willed her legs to function once more as she sketched a bow.

"I'm deeply sorry for the disturbance." She mumbled with what little air she'd managed to gain during her short respite and turned to leave.

"Wait," A slightly familiar voice called out to her, and she turned back towards the room and realized it was the Chinese man who she had run into the day before "you were being chased, right? It's alright, you can rest here, we won't harm you."

"Umm…" Tsuna fidgeted awkwardly, staring down at her hands. She didn't want to be rude, especially to the first person in the entire Academy who had shown her some form of kindness, but she equally didn't want to sit around a bunch of strangers for an indefinite amount of time. Unknown to Tsuna, her reluctance for the latter idea was shown clearly on her face, which surprised some of the occupants in the room since most of the student population would literally kill for such an opportunity. "I really don't want to intrude… Mister" Tsuna trailed of realizing that she actually didn't know the man's name.

"Oh, you aren't intruding at all, sweetie." One of the only two women in the room spoke up. She had a kind rounded face with a unique gold flower under her right eye and short black hair overshadowed by a large, puffy white hat. "Do you happen to know Fon?"

"Fon?" Tsuna tilted her head to the side in question.

"The man with the braid, honey." The kind woman gestured towards the man now known as Fon.

"Ah, no. We just happened to bump into each other yesterday. I'm sorry, I didn't catch your name then." Tsuna sketched another bow towards Fon as she apologized, realizing how rude she had sounded before.

"Not at all." Fon just smiled as he waved her concerns away. "But please, sit." He gestured towards a free seat beside himself and a man with a fedora.

"Uh, okay…" realizing it would only be even ruder to keep on refusing their offer, Tsuna meekly took a seat, shrinking in on herself when the fedora man turned his gaze at her. _So scary._

"So, who are you?" he asked. Now, Tsuna wasn't the type to go around looking for a fight, but even she expected others to follow common courtesy if the person wasn't obviously out to harm her.

"Hasn't anybody ever told you that you should introduce yourself first before asking the name of others?" The man seemed like he was going to say something, but was cut of by the bubbly woman.

"Oh, where are our manners? I'm Luce." She gazed expectantly to the hooded figure sitting next to her who was counting money. The figure sighed.

"Viper." Was all it said before going back to counting money. Another expectant gaze was directed to the green-haired man sitting on the other side of Viper.

"Verde" the man said without even looking up, dexterous fingers not missing a single beat as they tapped away at the laptop situated on his lap.

"I'm Colenello, kora!" shouted the laidback looking blond before getting cuffed in the head by the only other woman in the room.

"Lal Mirch" the pretty bluenette stated.

"Bask in my awesomeness! The great me is the daredevil Skull! Bow before m-" the hyperactive gothic man was cut of by a pillow smashing into his face with such force that he fell towards the floor.

"As Luce said, I'm Fon." The Chinese man smiled kindly at Tsuna who smiled back. Tsuna turned towards the last man to introduce himself.

"Chaos. I'm Reborn." The man who had obviously thrown the pillow stated while putting on an innocent air, like he was actually fooling anybody. Tsuna sweatdropped.

"Uh, hi. I'm Tsunayoshi Kuchiru. Nice to meet you." She bowed once more. "Um, if you don't mind me asking, why aren't any of you wearing school uniform?" she asked the question which had been bugging her for a while. A few eyebrows were raised at her question and the woman who called herself Luce spoke up.

"In this Academy, the strongest wielders of each flame from the 3 kingdoms are exempt from some restrictions, such as school uniform. We can wear what we like so long as the pin stating our year and flame ribbon are visible. The principle explained it during the opening ceremony, were you absent?"

"Ah, no, I was there. It does sound familiar…" Tsuna mumbled, embarrassed of not having known what seemed to be general knowledge in the Academy.

"She probably couldn't understand. She doesn't look all that bright." The fedora man- _Reborn_ her mind supplied her- stated. Tsuna flushed, whether from embarrassment or anger, she wasn't sure.

"Now Reborn, that wasn't very nice." Luce chided.

"Wait…" Tsuna froze as something occurred to her, "Does that mean that you guys are the strongest wielders of your kingdom?" she asked wide-eyed as she looked around the room. Reborn snorted.

"You just realised? This is the room the Principle set aside for the Arcobaleno group. That's why I said she wasn't bright." He addressed the last part of his sentence to Luce. "What year and flame are you anyway?" he drawled, looking as though he couldn't care less.

 _Ah, I see._ Tsuna mentally sighed. _They were treating me normally because they didn't know._ She smiled a little sadly beneath the cover of her fringe.

"I'm a middle school second year. Flame…" she gestured to her absence of ribbon. Understanding dawned the features of the room's occupants.

"Ah, I've heard of you, kora! Dame-Tsuna, right, kora?" Colenello shouted. Tsuna flinched, despite having known that it was coming. Almost mechanically, she jerked up and made to leave. Unfortunately, she toppled a glass over in her haste and brown liquid spilled across the table. Just as she was about to escape, Tsuna's hand was caught in a vice-like grip even as her other hand was settled on the knob of the door. She turned around and froze. Reborn's eyes bored into her own, slightly narrowed and exuding an acute killing intent which had every cell in her body screaming to _get the hell away now._

"You spilt my espresso."

"Uh, what?" Tsuna's brain still frozen in fear couldn't quite process this seemingly random statement.

"You. Spilt. My. Espresso." Reborn stated again. This time breaking the sentence word by word as if he were talking to a child, killer intent spiking with every syllable. "So make me another one." And with that, Tsuna was unceremoniously dumped into a kitchen, with a coffee machine and a bag of coffee beans. By the time Tsuna's mind stopped reeling and wondering _what the hell is going on_ , she found that she was alone in the kitchen and, not really knowing what else to do, decided to make the coffee by hand as she had long since realized that she and machines did not mix. It was a good thing she had learnt how to make coffee in one of her part-time jobs at a café. Ten minutes later, the espresso was done and she was re-entering the room, freshly brewed pot in hand.

"Uh," Colenello started sheepishly, looking as though he had gone through a rather tough beating if the large black bruises which were starting to appear were anything to go by, "sorry about what I said earlier. I didn't mean to insult you or anything." Tsuna wasn't sure what surprised her more, the fact that the blond was apologizing, or that he seemed to sincerely regret what he said. She felt a small smile grace her lips as she poured the espresso for the bast- for _Reborn_.

"Don't worry about it." There was a pregnant silence as Reborn sipped his drink, then poured himself another cup, and another. Soon, the pot was empty and Reborn finally spoke.

"Make me another cup, servant."

What. The. Hell.

"I am not your servant asshole! And why do I need to make you more? I only spilled one cup!"

"Please, if you think that pot of poorly made quality was worth it, then you're even dumber than I thought, slave."

"But you drank all of it! And why did my position go down?!"

"Tch. Didn't anyone ever tell you that it's bad to waste food _Dame-Tsuna_? I was thinking about the starving kids in Africa."

"Bullshit! You seem like the type of person who would enjoy seeing others suffer!" Tsuna had all but lost her meek person due to the constant mental stress her mind had been under since she'd entered this room. "Screw this, I'm outta here!" And with a loud bang, she was gone. Reborn simply tilted his fedora lower and laid back into his seat. Underneath the brim of his hat, however, there was a dangerous smirk making its way into his face. Tsuna was right, or course, Reborn really couldn't care less about the starving or suffering of others. After all, he _was_ the World's No. 1 Hitman for a reason.

 _The girl is interesting,_ Reborn thought, _and most of all, she makes good espresso._

"What a nice girl." Luce commented, "Reborn, why don't you _persuade_ her to come again tomorrow?"

Poor Tsuna. There was no way in hell she was getting away.

* * *

"I'm home." Tsuna mumbled as she took off her shoes in the entryway to the empty house- or, it _should_ have been an empty house.

"Welcome home, Tsuna." Tsuna jerked her head up.

"Sawada-sempai! What are you doing here?!" The blond lounging on her couch sighed in what seemed to be exasperation.

"Tsuna, what did I tell you about addressing me in private?" His tone was dead serious.

"But- Sawa-" Tsuna was cut off as those startlingly clear blue eyes narrowed, "Hai, Gio-nii" the blond, now known as Giotto, nodded in approval.

"That's more like it, Tsu-chan!" he replied, all earlier seriousness dissipated such that it almost seemed like an illusion. "Where were you? You usually come straight back here after classes." Tsuna sighed.

"I ran into some… people."

"People?" Giotto repeated, skepticism clear in his eyes.

"They said they were the Arcobaleno group or something. One of them- Reborn- was a real jerk. Hey, aren't they like you and your friends then? They said something about not having to wear school uniform as well." She carried on callously.

"What?!" Giotto had jumped of the couch and had a hand on each of Tsuna's shoulders. "Tsuna, please tell me you didn't get any of their attention, especially not Reborn." He screamed while shaking the poor girl back and forth.

"Gio-nii, stop shaking. Can't-" she was cut off as she started feeling slightly queasy, which got Giotto to stop panicking enough for Tsuna to catch her breath. "I don't think they really noticed me, half of them barely acknowledged my existence. In fact, what's most likely to get their attention is you being in my room which is why you _shouldn't be here!_ " Giotto shrunk back a little as the tables turned.

"But Tsu-chan! How could you do this to your brother?! Don't you love me? We're family, right? Right?! There are a lot of wolves out there you know? What kind of big brother would I be if I didn't come to check on my adorable little sister?!" he whined, on his knees and clinging onto her as he cried big, fat crocodile tears. Tsuna sweat dropped at his childishness.

"Gio-nii, don't be so loud. The neighbours will hear." She mumbled as she tried to pry the crying blond off her torso.

"Mother, father, Tsu-chan is ashamed of me! She doesn't even want people to know we're related. Oh, where did I go wrong raising her?!" He cried.

"Gio-nii," Tsuna lifted the blond's head up so his eyes met her own, "you know it's not like that." Giotto sobered immediately, a somber look plastered on his previously comedic face.

"I know Tsu-chan. But even if you've given up our name, you're still my little sister. I'll still worry about you. In the first place, all Vongola's hide their true last name until they graduate, the only difference with you is that you're not only hiding from the student population, but out family as well. They miss you, you know? They've never stopped looking. You can come back, you know that, right? We've always loved you and we always will."

"Yeah," Tsuna smiled, "and it's because I love you all as well that I can't come back. I don't want to see tou-san suffer because of me. I know it's selfish of me, wanting to make you watch me bear this curse alone, but I just don't have it in me to do the same for you. I don't want to see anyone I love suffer for my sake anymore." Tsuna felt tears start to prick at her eyes as she gazed into Giotto's own.

"No, Tsuna," Giotto stood and bundled his sister, his sweet, adorable, loving sister into his arms, "you are the most selfless person I know." The two of them stood there, in the middle of the living room as the little sister sobbed into her big brother's chest, and the big brother held on to the misfortunate girl who was fated to bear so much pain, far too early on in her short life. After what seemed like hours, though it had probably only been a few minutes, the girl's sobbing calmed and the brother lifted his sister's head this time to look once more into those warm chocolate eyes. "You will come back one day, right Tsu-chan?" he whispered softly, as though he were afraid that if the air was disturbed to greatly, the girl before him would shatter into a million pieces and be blown away with the wind.

"Yeah," the girl allowed herself a small smile, "one day, Gio-nii" and the two siblings shared a rare moment where the world seemed to only consist of the two of them, there in the middle of that living room. Both of them would have given anything to stay like that forever, in each other's loving embrace, deaf to the world outside. But they both knew far too well for children their age that some things came with too high a price, and neither of them had enough to pay for their dream.

"Hey Tsu-chan, I'm hungry. Sit down while I cook dinner." Giotto smiled down at the brunette in his arms. Tsuna was not fooled.

"No not step _one foot_ into my kitchen, Gio-nii!" she screamed, holding the blond in place and preventing him from advancing any further towards her love.

"Oh, come on Tsu-chan, I'm not _that_ bad!" Giotto whined, crocodile tears back in full force.

"Easy for you to say! It wasn't _your_ eyebrows that got burnt off the last time you stepped into a kitchen! You weren't even cooking anything, just boiling water. How does that even work?!" And just like that, the two siblings fell back into their usual banter, as though the solemn conversation that had occurred just moments were an illusion. They both knew better though, _this_ was the illusion. One that they were happy to play out while they still could.

Tbc.

* * *

 **Ookay. So I've been planning this for a while. Like, a long while, because there are a lot of plot holes to fill in, but I think I've got them all covered now? I hope so. Anyway, I hope you like this intro, though it was mostly just explaining everything in this world. Some of you may see the similarities, but yes, this story was inspired by a mix of Iris Zero and Black Haze. There will also be an element from another manga I no longer remember the name of since I read it ages ago, but it's more of a vague idea which inspired me, though it has a huge impact on the story, so I guess it's important.**

 **Grades:**

 **Grade 4 (Primary School) –Lambo, Ipin (10)**

 **Grade 6 (Primary School)- Fuuta, Yuni (12)**

 **2** **st** **Years (Middle School)- Tsuna, Gokudera, Yamamoto, Chrome (14)**

 **3** **rd** **Year (Middle School) -Hibari, Mukuro, Ryohei (15)**

 **1** **st** **Year (High School)- 1** **st** **Gen + Colonello, Skull + Byakuran (16)**

 **2** **nd** **Year (High School)- Rest of Arcobaleno (17)**


End file.
